Aim: To demonstrate that in patients with acute coronary syndrome (ACS), using Cordis 6F Infiniti diagnostic catheters for angioplasty may represent a safe alternative associated with lower contrast volume and radiation dosage, improving cardiovascular and renal outcomes. Material and Methods: In 1,800 patients with ACS (2,331 lesions/2,603 stents), angioplasty was performed with Cordis 6F Infiniti Thrulumen diagnostic catheters. Primary angioplasty was performed in 545 cases, and only balloon angioplasty in 67 patients. All procedures were performed through the femoral route, and switch-over to the radial route was made in 5 cases due to associated aortic/iliac obstructive lesions. Iodixanol was used in 76% of cases, and tirofiban in 99% of cases with adjusted dosages based on creatinine values. The mean contrast volume used per patient was 28 mL (± 6 mL) including the angiogram prior to the angioplasty. Results: The median fluoroscopy time was 4.4 min (IQR 3–6.8), the mean fluoroscopy time was 5.59 min (± 0.28), the median dose-area product or kerma-area product was 1,507 μGym2 (IQR 918–2,611), median total or cumulative dose including backscatter was 2,702 μGym2 (IQR 1,805–4,217), and the median cumulative skin dose was 468 mGy (IQR 296–722). Groin hematoma was seen in 7 cases, proximal mild edge dissection in the deployed stent in 3 cases, and acute in-hospital stent thrombosis in 7 cases. In total, 33 deaths were registered and 19 of these patients had cardiogenic shock, of which 11 subjects were late presenters. Three patients died after discharge due to possible acute stent thrombosis. Conclusions: Angioplasty and stenting can be performed safely in patients with acute coronary syndromes using Cordis 6F diagnostic catheters. The procedure was associated with a very low volume of contrast and radiation dose, leading to improved clinical outcomes.